Figure 3.

Alterations of the G₁/S transition regulators in NSCLC versus SCLC. Disruption of the G₁/S transition is a crucial event during lung carcinogenesis. Striking differences are observed regarding the mechanisms of G₁ escape in NSCLC versus SCLC. Pale grey circles indicate loss of expression of the corresponding protein and dark grey circles indicate overexpression. E2F1 and p15^INK4b are depicted by gradual color in NSCLC and SCLC respectively, as controversial results have been reported regarding their status in these tumors. In all other cases, abnormalities are very unfrequent or have not been studied. The percentage of dysregulation is presented next to each molecule.